Shopify designer and developer

I am looking for a Shopify designer and developer to update my existing Shopify store. I need someone who can make layout and design changes to my store to improve its overall appearance. I am not sure what specific theme or design I want, so I need someone who can provide suggestions based on my preferences. The ideal candidate should have experience in Shopify design and development, and be proficient in customizing Shopify themes. They should also have knowledge of Shopify apps and be able to optimize site speed and performance.